Dana Stubblefield, a former defensive lineman for the San Francisco 49ers walked into a San Francisco federal courtroom this morning and pleaded guilty to a felony charge of lying to federal agents about using performance-enhancing drugs in connection with the Balco steroids scandal.

The charge, which is set out in a three-page document unsealed today, includes one count of lying to lead Balco investigator Jeff Novitzky in November 2003 about receiving “the clear” and EPO, a blood-boosting drug, from the laboratory.

Stubblefield, accompanied by Palo Alto attorney Michael Armstrong, pleaded guilty before U.S. District Judge Susan Illston today. Under a plea deal, Stubblefield faces up to six months in prison.

Earlier today, he appeared before U.S. Magistrate Judge Elizabeth Laporte for his arraignment. Following procedure in federal court, he pleaded not guilty before Laporte, a plea he withdrew when he appeared before Illston.

Both he and his attorney declined to comment outside the courtroom.

The government alleges that Stubblefield lied about receiving performance-enhancing drugs from Balco president Victor Conte, just three days after the National Football League notified him that he had tested positive for THG, known as “the clear,” a steroid. Stubblefield was suspended for four games as a result of the test.

Novitzky shook Stubblefield’s hand as they waited for the court proceedings to begin.

The former defensive NFL rookie of the year is the latest casualty in the Balco scandal’s second chapter, which has focused on the prosecution of top athletes accused of lying to federal agents and a grand jury that probed the now-defunct Peninsula laboratory’s connection to doping in baseball, track, football and other sports.

The Justice Department’s biggest target thus far is former San Francisco Giants slugger Barry Bonds, indicted last fall on perjury and obstruction of justice charges for allegedly lying to the Balco grand jury in December 2003 about his use of steroids at the height of his career. The 43-year-old Bonds has pleaded not guilty to the charges.

Stubblefield, 37, was named by the Associated Press as defensive player of the year in 1997, when he had 15 sacks, following a dismal 1996 season. He was drafted by the 49ers in 1993. After 1997, he signed with the Washington Redskins, and returned to San Francisco in 2001 and 2002 and played with the Oakland Raiders as a free agent in 2003.

Stubblefield is now varsity defensive line coach for Valley Christian High School in San Jose, which he joined in 2005, two years after leaving professional football.

Earlier this month, disgraced former Olympics track hero Marion Jones was sentenced to six months in prison for lying during the Balco probe about her use of steroids after she pleaded guilty to false statement charges. Former track coach Trevor Graham and world-class cyclist Tammy Thomas are also awaiting trial in San Francisco federal court on charges of lying during the Balco investigation, further evidence of the government’s intent to punish athletes who did not tell the truth about their own doping when questioned about Balco.

The Balco case began more than five years ago with a raid on the Burlingame lab, which was later linked to dozens of athletes accused of using steroids to boost their careers. Former Balco president Victor Conte, as well as Balco vice president James Valente, later pleaded guilty to steroid distribution charges and served months in prison.

Greg Anderson, Bonds’ personal trainer and linked to Balco, also pleaded guilty to steroids charges. Anderson also served roughly a year in federal prison on contempt charges for refusing to testify before the grand jury investigating Bonds’ perjury allegations.

A long-awaited plan to keep the Raiders in Oakland was unveiled late Friday by city and Alameda County officials. In a news release issued late Friday afternoon, local officials touted the plan for a new $1.3 billion stadium and mixed-use development designed to keep the team at the Coliseum site. Raiders owner Mark Davis currently is pursuing a plan to...